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Taking people in United StatesPhase 3

A Trial of the Efficacy and Safety of a Fixed Dose of SEP-363856 in Adults With Generalized Anxiety Disorder

Key facts

Who runs it
Otsuka Pharmaceutical Development & Commercialization, Inc.
Where
Austin, Cherry Hill, Everett, Fairfax, Hallandale, Houston, Jamaica, Los Angeles, Memphis, Methuen, New York, Oklahoma City, Orlando, Philadelphia, Phoenix, Portland, Redlands, Sherman Oaks, The Bronx, Valley Village, and Watertown, United StatesSee the 21 sites
Status
Recruiting
Phase
Phase 3
People taking part
384 people, planned
Started
6 Aug 2026
Expected to end
1 Nov 2028
Type of study
Interventional, 2 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • SEP-363856
  • Placebo
Record updated
12 November 2026

Who can take part

Age
18 years and older
Sex
Women and men
Healthy volunteers
Cannot take part

The registry criteria, word for word

Show all 17 criteriaShow less

Who can take part

  • Male or female participants at least 18 years of age at the time of informed consent
  • Primary diagnosis of GAD per Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), confirmed by Mini-International Neuropsychiatric Interview (MINI) and clinical psychiatric evaluation
  • Body Mass Index (BMI) 18-40 kilograms per square meter (kg/m\^2)
  • Participant is willing and able to comply with study procedures and visit schedule
  • Medically stable as determined by medical history, physical exam, vital signs, and laboratory tests and able to comply with study procedures
  • Willing and able to discontinue prohibited medications/therapies per protocol
  • (i ) Females of childbearing potential: negative pregnancy test and agreement to use acceptable contraception (ii) Males: agreement to follow protocol-defined contraception and reproductive restrictions
  • Willing and able to discontinue prohibited medications/therapies per protocol

Who cannot take part

  • Current DSM-5 diagnosis of major depressive episode, post traumatic stress disorder (PTSD), or any psychiatric disorder other than GAD that was the primary focus of treatment within 12 months prior to screening
  • Substance use disorder (excluding nicotine/caffeine) within 12 months prior to screening
  • Use of prohibited medications/therapies within protocol-defined timeframes (e.g., certain antipsychotics, mood stabilizers, benzodiazepines, investigational treatments)
  • Prior exposure to restricted treatments
  • Lifetime history of certain psychiatric disorders (e.g., schizophrenia spectrum disorders, bipolar disorder, obsessive-compulsive disorder, borderline or antisocial personality disorder)
  • Known history of human immunodeficiency virus seropositivity, hepatitis B or C
  • Significant suicide risk e.g., recent suicidal behavior/ideation per Columbia-Suicide Severity Rating Scale [C-SSRS] or MADRS)
  • Pregnant or breastfeeding females
  • Participation in another investigational study within 180 days (or more than [>] 1 trial in last year)

Where in United States

  • Donald J Garcia Jr, MD, PAAustin, United StatesContact: Garcia (principal investigator)Taking people
  • Lumina Clinical Research CenterCherry Hill, United StatesContact: Corcoran (principal investigator)Taking people
  • Core Clinical ResearchEverett, United StatesContact: Knutson (principal investigator)Taking people
  • Vitra Behavioral and Metabolic Research CenterFairfax, United StatesContact: Bahroo (principal investigator)Taking people
  • Velocity Clinical Research, Hallandale BeachHallandale, United StatesContact: Safirstein (principal investigator)Taking people
  • DM Clinical Research - BellaireHouston, United StatesContact: Karakoc (principal investigator)Taking people
  • Basil ClinicalJamaica, United StatesContact: Rapp (principal investigator)Taking people
  • CalNeuro Research GroupLos Angeles, United StatesContact: Bystritsky (principal investigator)Taking people
  • CNS Healthcare - MemphisMemphis, United StatesContact: Arnold (principal investigator)Taking people
  • ActivMed Practices & Research, LLCMethuen, United StatesContact: Shay (principal investigator)Taking people
  • IMA Clinical Research - NYC UptownNew York, United StatesContact: Careri (principal investigator)Taking people
  • Paradigm Research Professionals, LLCOklahoma City, United StatesContact: Herring (principal investigator)Taking people
  • Clinical Neuroscience Solutions Inc. (CNS) - OrlandoOrlando, United StatesContact: Molpus (principal investigator)Taking people
  • Adams Clinical PhiladelphiaPhiladelphia, United StatesContact: Blanchard (principal investigator)Taking people
  • IMA Clinical Research PhoenixPhoenix, United StatesContact: Sadr (principal investigator)Taking people
  • Summit Research NetworkPortland, United StatesContact: Essink (principal investigator)Taking people
  • Anderson Clinical ResearchRedlands, United StatesContact: Anderson (principal investigator)Taking people
  • Schuster Medical Research Institute SMRISherman Oaks, United StatesContact: Itzcovich-Schuster (principal investigator)Taking people
  • Adams Clinical BronxThe Bronx, United StatesContact: Farooq (principal investigator)Taking people
  • Concierge Clinical TrialsValley Village, United StatesContact: Cutler (principal investigator)Taking people
  • Adams Clinical WatertownWatertown, United StatesContact: Ellickson (principal investigator)Taking people

About the trial

What the trial wants to find out

This is a global, phase 3, randomized, double-blind, parallel-group, 2-arm, placebo controlled, multicenter trial designed to compare the efficacy, safety and tolerability of a fixed dose of SEP-363856 (75 millligrams per day [mg/day]) to placebo over an 8-week double-blind treatment period in adults with generalized anxiety disorder (GAD).

The 2 groups in the trial

  • SEP-363856Treatment being tested

    Participants will receive SEP-363856, 50 mg (Days 1 to 3) and 75 mg/day tablet, from Days 4 to 56, orally, QD.

  • PlaceboPlacebo, for comparison

    Participants will receive SEP-363856-matching placebo tablet, orally, QD from Days 1 to 56.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Phase 3, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled, Multicenter Trial to Compare the Efficacy and Safety of a Fixed Dose of SEP-363856 to Placebo in the Treatment of Adults With Generalized Anxiety Disorder
Record updated
12 November 2026